Piston.



UNITED STATES Patented April 18, 1905.

PATENT OFFICE.

DEAN O. LEWIS,- OF ARDMORE, PENNSYLVANIA, ASSIGNOR TO THE AUTO- OAR COMPANY, OF ARDMORE, PENNSYLVANIA.

PENNSYLVANIA, A CORPORATION PISTON.

SPECIFICATION forming part of Letters Patent No. 787,775, dated April 18, 1905.

Application filed December 29, 1904. Serial No. 238,765.

To all whmn it may concern:

Beit known that I, DEAN O. LEWIS, a citizen of the United States, residing at Ardmore,

county of Montgomery, and State of Pennsylvania, have invented a new and useful Improvement in Pistons, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, which form a part of this specification.

My invention relates to pistons for gasolene or other engines in which the piston-rod is detachably secured to the piston.

The object of the invention is to enable the piston to be readily and quickly secured to and detached from the piston-rod.

In the drawings, Figure 1 is a sectional view through the cylinder, showing the packing-rings and the connection between the piston and connecting-rod. Fig. 2 is a section on the line 2 2, Fig. 1. Fig. 3 is a detail of the ends of the packing-ring.

a is the cylinder; 6, the hollow cylindrical portion of the piston; 0, the follower, head,

' or cap of the piston, and (Z the piston-rod.

The cylindrical portion of the piston is provided with two oppositely-disposed holes 6 0 and bosses f g, coinciding with said holes and projecting inwardly toward and in alinement with each other.

it is a cylindrical-shaped cross-pin the diameters of the ends of which are substantially equal to the diameters of the bosses f and g, respectively.

2' is a sleeve on the end of the piston-rod (Z. The sleeve incloses a bushing j.

is is a radial orifice formed in one end of the cross-pin 7. Z is a coil-spring seated within said orifice.

m is an orifice of somewhat smaller diameter than orifice it, formed in the boss f. The wall of the boss f is preferably thickened at the point at which the orifice m is formed therein.

92 is a locking-pin having a body of substantially the diameter of orifice 7c and a reduced end of substantially the diameter of orifice m.

The method of attaching the piston-rod to the piston is as follows: The piston-rod isinserted within the piston so that its end sleeve is in alinement with the bosses f and g. The cross-pin 7b is then inserted, the unorificed end of the cross-pin being introduced into orifice c and thence passed successively through boss f, sleeve '5, and boss 9 into orifice 0, the orificed end of the pin then resting in orifice e and boss f. The pin then fits snugly within the bosses of the piston and the sleeved end of the piston rod. Before .the introduction of the cross-pin h the enlarged end of the pin n is inserted into the orifice 7c of the cross-pin and forcibly pressed toward the bottom of the orifice, so as to bring the reduced end of the pin flush with or slightly below the mouth of the orifice, thereby permitting the cross-pin to be inserted. After the cross-pin is pushed into position it is turned on its axis, if necessary, to bring the pin it into alinement with the orifice m in the boss f, whereupon the spring Z causes the reduced end of the pin to enter the orifice m. This looks the cross-pin to the boss f, and thus firmly secures together the piston rod and the piston-head. The shoulder formed at the junction of the enlarged and reduced end of the locking-pin impinges against the wall of the boss surrounding the edge of orifice m and limits the eX- tent to which the pin is projected within orifice m.

The piston is constructed in the usual manner to receive the packing, the rear end of the piston being provided with an internal flange on the outside of which is formed an annular groove for reception of the packingring and the end of the piston being provided with an internal flange on the outside of which is formed an annular groove for the reception of the packing-rings r, s, and t. The packing-rings 1' and s are split rings. The packing-ring t is a continuous ring of less thickness than the split rings. The opposite ends of each split ring are cut away on opposite sides, respectively, for about half their thickness to form projections u u, the projection of each end extending into the cutaway portion of the other end. Thus the rings are capable of expansion as the cylinder wears.

I have arranged the overlapping ends of ring 0" on that side of the piston opposite the overlapping ends of ring This is advantageous in that if the overlapping ends of the two rings were arranged on the same side of the piston the danger of leakage would be increased by the provision of a direct path for the escape of the motive fluid from between the piston and cylinder i successively inside ring 9, outside ring 25, and inside ring a. By arranging the interlocking ends on opposite sides of the piston no direct path for the escape of the motive fluid can at any time exist, as the motive fluid in order to get from one split ring to the other would, under the most favorable conditions, be compelled to pass between the continuous ring and the cylinder for half the circumference of the piston. In order to insure the rings 0' and a "maintaining this desired relative position, I provide the continuous ring with a pin 4), projecting from opposite faces thereof and entering orifices formed in the abutting faces of the split rings. Thus all three rings are locked together, and while they are free to turn bodily together neither split ring can turn in relation to the other.

To hold the packing-rings in position and maintain them in close contact with each other, the usual practice is to provide a follower, head, or cap secured to the piston in any convenient way and pressing against the pack- "ing. When the piston is made of hollow cylindrical shape, as shown, I find it most convenient to provide the cap with a threaded flange w, engaging a thread m on the flanged upper end of the piston.

The connection between the piston and the piston-rod is such as to enable their disengagement to be effected speedily, it being only necessary to insert a convenient tool into the orifice m of the boss f and press the pin out of said orifice, whereupon the cross-pin may be at once withdrawn.

Having now fully described my invention, what I claim, and desire to protect by Letters Patent, is

1. The combination, with a piston and piston-rod, of alining orifices in the same, a pin seated in one orifice and extending into the other orifice, and a spring in the first orifice tending to maintain the pin in its extended position, substantially as described.

2. The combination, with a piston and piston-rod, of alining orifices ofdifferentdiameters in the piston and piston-rod respectively, a spring in the orifice of greater diameter, and a pin having its ends relatively enlarged and reduced, the enlarged end being seated in the orifice of greater diameter and being pressed outwardly by the spring therein so as to project and hold the reduced end in the orifice of smaller diameter, substantially as described.

3. The combination, with a piston having an inwardly-extending boss and a piston-rod having a cross-pin extending within said boss, of alining orifices in the said cross-pin and boss, and a springpressed locking pin engaging both orifices, substantially as described.

4;. The combination, with a piston having inwardly-projecting hollow bosses, and a piston-rod having a cross-pin adapted to enter said bosses, there being an orifice in the crosspin adapted to aline with an orifice in one of the bosses, of a spring seated in the orifice in the cross pin, and a loclzingpin extending into both orifices and held within the orifice in the boss by means of the spring, substantially as described.

5. The combination, with a piston having inwardly-projecting hollow bosses and a piston-rod having a cross-pin adapted to enter said bosses, there being an orifice in the cross-pin and an alining orifice of smaller diameter extending through one of the bosses, of a lockingpin having its ends relatively enlarged and reduced, the enlarged end of the pin extending into the orifice in the cross-pin and the reduced end of the pin extending into the orifice in the boss, and a spring seated in the orifice in the cross-pin and so projecting the locking-pin into the orifice in the boss, substantially as described.

In testimony of which invention I have hereunto set my hand, at Ardmore, Pennsylvania, on this 23d day of December, 1904.

DEAN C. LEWIS.

Witnesses:

Vivi. J. Scorr, ROBERT E. KAIN. 

